Recovery and long-term outcome after neurosurgical closure of spinal CSF leaks in patients with spontaneous intracranial hypotension.

INTRODUCTION: Spontaneous intracranial hypotension due to a spinal cerebrospinal fluid leak causes orthostatic headaches and impacts quality of life. Successful closure rates are often reported, whereas data on long-term outcome are still scarce. METHODS: Between April 2020 and December 2022 surgically treated patients completed the Headache Impact Test-6 prior to surgery and at 14 days, three months, six months, and 12 months postoperatively. In addition to the Headache Impact Test-6 score, we extracted data related to orthostatic symptoms. RESULTS: Eighty patients were included. Median Headache Impact Test-6 score preoperatively was 65 (IQR 61-69), indicating severe and disabling impact of headaches. At three months headache impact significantly improved to 49 (IQR 44-58) (p < 0.001) and remained stable up to 12 months (48, IQR 40-56), indicating little to no impact of headaches on quality of life. The need to lie down "always" or "very often" was reduced from 79% to 23% three months postoperatively (p < 0.001). CONCLUSIONS: Surgical closure of spinal CSF leaks significantly improves the impact of headaches in the long term. At least three months should be expected for recovery. Despite permanent closure of the CSF-leak, a quarter of patients still have relevant long-term impairment, indicating the need for further research on its cause and possible treatment.

Intraoperative Visualization of Flow in Direct Cerebrospinal Fluid-Venous Fistulas Using Intrathecal Fluorescein.

BACKGROUND: Cerebrospinal fluid-venous fistulas (CVFs) are a rare cause of spontaneous intracranial hypotension. Intraoperatively, CVFs are not readily identifiable and difficult to differentiate from normal veins. OBJECTIVE: To assess the utility of intrathecal fluorescein injection intraoperatively to visualize and identify the CVF. METHODS: We report a case series of patients treated surgically for a CVF. After surgical exposure, we injected intrathecal fluorescein (5-10 mg) through a lumbar catheter, which we placed immediately before surgery. RESULTS: Four patients with spontaneous intracranial hypotension with a suspected CVF underwent surgical ligation with adjunctive intrathecal fluorescein application. Intraoperative fluorescein injection confirmed the presence of a CVF in 3 cases. In 2 cases, we observed rapid fluorescein filling of a single epidural vein constituting the CVF. Other epidural vessels did not fill with fluorescein. In 1 case, fluorescein helped to identify a residual CVF after previous incomplete embolization. In the fourth case, no CVF was found intraoperatively. By contrast, a meningeal nerve root diverticulum was visualized, wrapped, and clipped. CONCLUSION: We demonstrate for the first time the direct intraoperative visualization of CVF using intrathecal fluorescein. CVF can be identified intraoperatively using fluorescein dye, which can be a valuable adjunct for the surgeon confronted with this disease.

Postoperative Spinal Cerebrospinal Fluid-Venous Fistulas Associated With Dural Tears in Patients With Intracranial Hypotension or Superficial Siderosis-A Digital Subtraction Myelography Study.

BACKGROUND: Postoperative spinal cerebrospinal fluid (CSF) leaks are common but rarely cause extensive CSF collections that require specialized imaging to detect the site of the dural breach. OBJECTIVE: To investigate the use of digital subtraction myelography (DSM) for patients with extensive extradural CSF collections after spine surgery. METHODS: A retrospective review was performed to identify a consecutive group of patients with extensive postoperative spinal CSF leaks who underwent DSM. RESULTS: Twenty-one patients (9 men and 12 women) were identified. The mean age was 46.7 years (range, 17-75 years). The mean duration of the postoperative CSF leak was 3.3 years (range, 3 months to 21 years). MRI showed superficial siderosis in 6 patients. DSM showed the exact location of the CSF leak in 19 (90%) of the 21 patients. These 19 patients all underwent surgery to repair the CSF leak, and the location of the CSF leak could be confirmed intraoperatively in all 19 patients. In 4 (19%) of the 21 patients, DSM also showed a CSF-venous fistula at the same location as the postoperative dural tear. CONCLUSION: In this study, DSM had a 90% detection rate of visualizing the exact site of the dural breach in patients with extensive postoperative spinal CSF leaks. The coexistence of a CSF-venous fistula in addition to the primary dural tear was present in about one-fifth of patients. The presence of a CSF-venous fistula should be considered if CSF leak symptoms persist in spite of successful repair of a durotomy.

Spontaneous intracranial hypotension: from cerebral venous thrombosis to neurosurgical treatment: a case series experience from a Brazilian tertiary health care center.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a secondary cause of headache and an underdiagnosed disease. The clinical presentation can be highly variable. It typically presents with isolated classic orthostatic headache complaints, but patients can develop significant complications such as cerebral venous thrombosis (CVT). OBJECTIVE: To report 3 cases of SIH diagnosis admitted and treated in a tertiary-level neurology ward. METHODS: Review of the medical files of three patients and description of clinical and surgical outcomes. RESULTS: Three female patients with SIH with a mean age of 25.6 ± 10.0 years old. The patients had orthostatic headache, and one of them presented with somnolence and diplopia because of a CVT. Brain magnetic resonance imaging (MRI) ranges from normal findings to classic findings of SIH as pachymeningeal enhancement and downward displacement of the cerebellar tonsils. Spine MRI showed abnormal epidural fluid collections in all cases, and computed tomography (CT) myelography could determine an identifiable cerebrospinal fluid (CSF) leak in only one patient. One patient received a conservative approach, and the other two were submitted to open surgery with laminoplasty. Both of them had uneventful recovery and remission in surgery follow-up. CONCLUSION: The diagnosis and management of SIH are still a challenge in neurology practice. We highlight in the present study severe cases of incapacitating SIH, complication with CVT, and good outcomes with neurosurgical treatment.

ANTECEDENTES: Hipotensão intracraniana espontânea (HIE) é uma causa secundária de cefaleia e uma doença subdiagnosticada. A apresentação clínica pode ser muito variável. Tipicamente, se apresenta com queixas isoladas de cefaleia ortostática clássica, porém pode evoluir com complicações significativas como trombose venosa cerebral (TVC). OBJETIVO: Relatar 3 casos de diagnóstico de hipotensão intracraniana espontânea manejados em uma enfermaria de neurologia de nível terciário. MéTODOS: Revisão dos prontuários de três pacientes e descrição dos resultados clínicos e cirúrgicos. RESULTADOS: Três pacientes do sexo feminino com média de idade de 25.6 ± 10.0 anos. As pacientes apresentavam cefaleia ortostática e uma delas apresentou sonolência e diplopia devido a TVC. A ressonância magnética (RM) do encéfalo varia de achados normais até achados clássicos de HIE como realce paquimeníngeo e deslocamento inferior das tonsilas cerebelares. A RM da coluna mostrou coleções anormais de líquido epidural em todos os casos e a mielografia por tomografia computadorizada (TC) foi capaz de determinar fístula liquórica identificável em apenas uma paciente. Uma paciente recebeu abordagem conservadora e as outras duas foram submetidas a cirurgia aberta com laminoplastia. Ambas tiveram recuperação e remissão sem intercorrências no seguimento cirúrgico. CONCLUSãO: O diagnóstico e manejo da hipotensão intracraniana ainda são desafios na prática neurológica. Destacamos no presente estudo casos graves, complicação com TVC e bons resultados com tratamento neurocirúrgico.

Minimally invasive surgery for spinal cerebrospinal fluid leaks in spontaneous intracranial hypotension.

OBJECTIVE: Spinal CSF leaks cause spontaneous intracranial hypotension (SIH). Surgical closure of spinal CSF leaks is the treatment of choice for persisting leaks. Surgical approaches vary, and there are no studies in which minimally invasive techniques were used. In this study, the authors aimed to detail the safety and feasibility of minimally invasive microsurgical sealing of spinal CSF leaks using nonexpandable tubular retractors. METHODS: Consecutive patients with SIH and a confirmed spinal CSF leak treated at a single institution between April 2019 and December 2020 were included in the study. Surgery was performed via a dorsal 2.5-cm skin incision using nonexpandable tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach. The primary outcome was successful sealing of the dura, and the secondary outcome was the occurrence of complications. RESULTS: Fifty-eight patients, 65.5% of whom were female (median age 46 years [IQR 36-55 years]), with 38 ventral leaks, 17 lateral leaks, and 2 CSF venous fistulas were included. In 56 (96.6%) patients, the leak could be closed, and in 2 (3.4%) patients the leak was missed because of misinterpretation of the imaging studies. One of these patients underwent successful reoperation, and the other patient decided to undergo surgery at another institution. Two other patients had to undergo reoperation because of insufficient closure and a persisting leak. The rate of permanent neurological deficit was 1.7%, the revision rate for a persisting or recurring leak was 3.4%, and the overall revision rate was 10.3%. The rate of successful sealing during the primary closure attempt was 96.6% and 3.4% patients needed a secondary attempt. Clinical short-term outcome at discharge was unchanged in 14 patients and improved in 25 patients, and 19 patients had signs of rebound intracranial hypertension. CONCLUSIONS: Minimally invasive surgery with tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach is safe and effective for the treatment of spinal CSF leaks. The authors suggest performing a minimally invasive closure of spinal CSF leaks in specialized centers.

Surgical management of spontaneous intracranial hypotension syndrome: a literature review.

INTRODUCTION: Spontaneous intracranial hypotension (SIH) is a highly disabling but often misdiagnosed disorder. The optimal management options for patients with SIH remain uncertain. The aim of this study was to review studies reporting the management of SIH with a special emphasis on the surgical treatment of SIH including clinical trials, case series and case reports related to the issue of various neurosurgical procedures performed for SIH treatment. OBJECTIVE: The clinical outcomes of patients diagnosed with SIH treated with either only surgery or with surgery as the primary method of treatment were analysed. MATERIAL AND METHODS: The PubMed, Scopus and Google Scholar databases were searched according to the established criteria. RESULTS: The literature search revealed seven clinical trials, five case series and eight case reports regarding surgical treatment of patients diagnosed with SIH. Manuscripts reporting at least five individuals treated surgically for SIH were considered as case series. In most published articles, surgery provided clinical benefit, resulting in a success rate of 82.6-100% for complete relief of SIH symptoms. CONCLUSIONS: Our literature review has revealed that SIH can be diagnosed reliably by MRI and cisternography. The identification of the location of SIH is mandatory for its successful surgical treatment. The clinical outcome is related to the location of SIH in the spinal canal. Most often, cerebrospinal fluid leakage occurs in the thoracic region. Surgical treatment is very effective and the obtained treatment results are complete and permanent. of the location of SIH is mandatory for its successful surgical treatment. The clinical outcome is related to the location of SIH in the spinal canal. Most often, cerebrospinal fluid leakage occurs in the thoracic region. Surgical treatment is very effective and the obtained treatment results are complete and permanent.

Full Endoscopic Repair of Spontaneous Ventral Cerebrospinal Fluid Leaks in the Spine: Systematic Review of Surgical Treatment Options and Illustrative Case.

BACKGROUND: Spontaneous spinal cerebrospinal fluid (CSF) leaks are a rare entity that can lead to intracranial hypotension and associated headaches, meningismus, and patient debility. Surgical treatment may be necessary for patients who do not respond to conservative management. Surgical repair of CSF leaks located in the ventral thoracic spine traditionally require an invasive, open approach. METHODS: We describe the case of a patient with a ventral thoracic spontaneous spinal CSF leak associated with a ventral bony osteophyte successfully treated with spinal endoscopy. We also provide a systematic review of the literature to better understand outcomes of this approach. RESULTS: A total of 55 patients were included in the systematic review. The study designs found in the literature review included case reports (66.7%), retrospective cohorts (22.2%), and prospective cohorts (11.1%). Of the studies reporting data, 50% of studies stated they used an open posterior approach to the dural defect, while 37.5% reported using an open anterior approach to the pathology. Only 1 (12.5%) study reported using an endoscope. Most studies (62.5%) used primary closure of the dura in their technique, while 37.5% reported using a local tissue graft (fat or muscle) or a dural sealant for their closure technique, and 25% of studies reported using a dural substitute for their closure technique. Overall mean clinical follow-up was 19.8 months. CONCLUSIONS: The endoscopic approach described here for treatment of this rare entity allows for removal of bony spicules/osteophytes and dural repair without the morbidity associated with traditional open dorsolateral or ventrolateral approaches.

How I do it: the trans-laminar, facet-joint sparing minimal invasive approach for ventral dural repair in spontaneous intracranial hypotension-a 2-dimensional operative video.

BACKGROUND: We describe the minimally invasive, facet-sparing postero-lateral approach to the thoracic spine for a ventral dural repair in a patient with intracranial hypotension secondary to a spontaneous dural breach. METHODS: We performed a minimally invasive approach using a short paramedian posterior skin incision followed by a 10 × 10 mm targeted trans-laminar approach, to achieve a microsurgical repair of a symptomatic ventral dural defect causing severe disability. CONCLUSION: The facet-sparing postero-lateral approach is safe and effective in the surgical management of thoracic dural tears, even in the most anterior ones, and avoids the traditional costotransversectomy.

Intradural extraarachnoid sutureless technique combined with laminoplasty for indirect repair of ventral dural defects in spontaneous intracranial hypotension: technical note and case series.

BACKGROUND: There is a significant variance in surgical treatment strategies of ventral cerebrospinal fluid (CSF) leaks causing spontaneous intracranial hypotension (SIH). Posterior approaches might represent a preferable alternative to the more invasive anterior and lateral routes, as long as the spinal cord is not exposed to harmful manipulation. The aim of this technical note is to report and illustrate a new surgical technique using an intradural extraarachnoid sutureless technique via laminoplasty for indirect repair of ventral CSF leaks causing intractable SIH symptoms. METHODS: The surgical technique is described in a step by step fashion. Between May 2018 and May 2020, five patients with ventral spinal CSF leaks were operated on, utilizing this technique. All dural defects were located at the level of the thoracic spine. A retrospective review on demographic and radiological findings, symptoms, outcome, and follow-up was performed. RESULTS: The intra- and postoperative course was uneventful in all patients with no surgery-related complications. Three patients recovered completely at discharge, while neurological symptoms significantly improved in two patients. A postoperative MRI of the spine was obtained for all patients, demonstrating regressive signs of CSF leak. CONCLUSION: Based on the presented case series, this intradural extraarachnoid sutureless technique combined with laminoplasty seems to be a safe and effective option for indirect repair of ventral dural defects in SIH. In our opinion, it represents a valid alternative to traditional more aggressive approaches.

Monro-Kellie Hypothesis: Increase of Ventricular CSF Volume after Surgical Closure of a Spinal Dural Leak in Patients with Spontaneous Intracranial Hypotension.

BACKGROUND AND PURPOSE: CSF loss in spontaneous intracranial hypotension disrupts a well-regulated equilibrium. We aimed to evaluate the volume shift between intracranial compartments in patients with spontaneous intracranial hypotension before and after surgical closure of the underlying spinal dural breach. MATERIALS AND METHODS: In total, 19 patients with spontaneous intracranial hypotension with a proved spinal CSF leak investigated at our institution between July 2014 and March 2017 (mean age, 41.8 years; 13 women) were included. Brain MR imaging-based volumetry at baseline and after surgery was performed with FreeSurfer. In addition, the spontaneous intracranial hypotension score, ranging from 0 to 9, with 0 indicating very low and 9 very high probability of spinal CSF loss, was calculated. RESULTS: Total mean ventricular CSF volume significantly increased from baseline (15.3 mL) to posttreatment MR imaging (18.0 mL), resulting in a mean absolute and relative difference, +2.7 mL and +18.8% (95% CI, +1.2 to +3.9 mL; P < .001). The change was apparent in the early follow-up (mean, 4 days). No significant change in mean total brain volume was observed (1136.9 versus 1133.1 mL, P = .58). The mean spontaneous intracranial hypotension score decreased from 6.9 ± 1.5 at baseline to 2.9 ± 1.5 postoperatively. CONCLUSIONS: Our study demonstrated a substantial increase in ventricular CSF volume in the early follow-up after surgical closure of the underlying spinal dural breach and may provide a causal link between spinal CSF loss and spontaneous intracranial hypotension. The concomitant decrease in the spontaneous intracranial hypotension score postoperatively implies the restoration of an equilibrium within the CSF compartment.

Superficial siderosis and intracranial hypotension syndrome following brachial plexus avulsion injury. A case of surgical treatment.

Superficial siderosis (SS) is a slowly progressive neurodegenerative disorder caused by persistent or intermittent bleeding into the subarachnoid space. It leads to characteristic clinical and radiographic findings. Dural pathology is believed to be the most common identifiable etiology of SS. It has been suggested that dural tear may be the common pathology of both SS and intracranial hypotension syndrome. We present a patient with SS caused by posttraumatic duropathy that was associated with cerebrospinal fluid (CSF) hypotension headache. Patient was treated surgically with stabilization of neurological deficit and orthostatic headache improvement. It supports the speculated link between both entities and may confirm surgery being a reasonable approach in patients with SS.

Clinical Outcomes Following Surgical Ligation of Cerebrospinal Fluid-Venous Fistula in Patients With Spontaneous Intracranial Hypotension: A Prospective Case Series.

BACKGROUND: Cerebrospinal fluid-venous fistula (CVF) is a recently described cause of spontaneous intracranial hypotension (SIH). Surgical ligation of CVF has been reported, but clinical outcomes are not well described. OBJECTIVE: To determine the clinical efficacy of surgical ligation for treatment of CVF. METHODS: Outcomes metrics were collected in this prospective, single-arm, cross-sectional investigation. Inclusion criteria were as follows: diagnosis of SIH, demonstration of CVF on myelography, and surgical treatment of CVF. Pre- and postoperative headache severity was assessed with the Headache Impact Test (HIT-6), a validated headache scale ranging from 36 (asymptomatic) to 78 (most severe). Patient satisfaction with treatment was measured with Patient Global Impression of Change (PGIC). RESULTS: Twenty subjects were enrolled, with mean postoperative follow-up at 16.0 ± 9.7 mo. All CVFs were located in the thoracic region (between T4 and T12). Pretreatment headache severity was high (mean HIT-6 scores 65 ± 6). Surgical treatment resulted in marked improvement in headache severity (mean HIT-6 change of -21 ± -9, mean postoperative HIT-6 of 44 ± 8). Of subjects with baseline headache scores in the most severe category, 83% showed a major improvement in severity (transition to the lowest 2 severity categories) after surgery. All subjects (100%) reported clinically significant levels of satisfaction with treatment (PGIC score 6 or 7); 90% reported the highest level of satisfaction. There were no short- or long-term complications or 30-d readmissions. CONCLUSION: Surgical ligation is highly effective for the treatment of SIH due to CVF. Larger controlled trials with longer follow-up period are indicated to better assess its long-term efficacy and safety profile.

Chiari I malformation and altered cerebrospinal fluid dynamics-the highs and the lows.

PURPOSE: This paper reviews the altered cerebrospinal fluid dynamics that can be associated with paediatric Chiari I malformation and we present our own institutional experience. METHODS: We conducted a thorough review of the literature and retrospectively analyzed all cases of operatively managed paediatric Chiari 1 malformation at our institution between February 2006 and February 2019. RESULTS: Acquired Chiari malformation (ACM) can radiologically mimic Chiari I and has been associated with both intracranial hypotension (either secondary to lumboperitoneal shunting or spontaneous CSF hypotension) and idiopathic intracranial hypertension (IIH). At our institution, 61 paediatric cases (range, 2-15 years) underwent foramen magnum decompression (FMD) for Chiari I malformation. Whilst 80% (50/61) of cases underwent FMD with no preceding or post-operative problems of CSF dynamics, 8% (5/61) of cases had hydrocephalus at initial presentation requiring CSF diversion followed by FMD for persistent Chiari, and 10% (6/61) developed hydrocephalus following FMD and required long-term CSF diversion. CONCLUSIONS: In paediatric ACM, the management of intracranial hypotension involves thorough radiological assessment and inclusion/adjustment of a valve in the case of lumboperitoneal shunting or epidural blood patch or interventional techniques in the case of spontaneous CSF leak. Thereby, unwarranted posterior fossa decompression surgery is avoided. In the case of IIH and Chiari I malformation, children who have recurrent symptoms despite adequate posterior fossa decompression surgery (failed Chiari), there is a strong role for intracranial pressure monitoring as raised intracranial pressure may indicate long-term CSF diversion.

Posterior Approach and Spinal Cord Release for 360° Repair of Dural Defects in Spontaneous Intracranial Hypotension.

BACKGROUND: Spinal cerebrospinal fluid (CSF) leaks are the cause of spontaneous intracranial hypotension (SIH). OBJECTIVE: To propose a surgical strategy, stratified according to anatomic location of the leak, for sealing all CSF leaks around the 360° circumference of the dura through a single tailored posterior approach. METHODS: All consecutive SIH patients undergoing spinal surgery were included. The anatomic site of the leak was exactly localized. We used a tailored hemilaminotomy and intraoperative neurophysiological monitoring (IOM) for all cases. Neurological status was assessed before and up to 90 d after surgery. RESULTS: Forty-seven SIH patients had an identified CSF leak between the levels C6 and L1. Leaks, anterior to the spinal cord, were approached by a transdural trajectory (n = 28). Leaks lateral to the spinal cord by a direct extradural trajectory (n = 17) and foraminal leaks by a foraminal microsurgical trajectory (n = 2). The transdural trajectory necessitated cutting the dentate ligament accompanied by elevation and rotation of the spinal cord under continuous neuromonitoring (spinal cord release maneuver, SCRM). Four patients had transient defiticts, none had permanent neurological deficits. We propose an anatomic classification of CSF leaks into I ventral (77%, anterior dural sac), II lateral (19%, including nerve root exit, lateral, and dorsal dural sac), and III foraminal (4%). CONCLUSION: Safe sealing (with IOM) of all CSF leaks around the 360° surface of the dura is feasible through a single posterior approach. The exact surgical trajectory is selected according to the anatomic category of the leak.

Sonography of the optic nerve sheath diameter before and after microsurgical closure of a dural CSF fistula in patients with spontaneous intracranial hypotension - a consecutive cohort study.

OBJECTIVE: Spontaneous intracranial hypotension is caused by spinal cerebrospinal fluid leakage. Patients with orthostatic headaches and cerebrospinal fluid leakage show a decrease in optic nerve sheath diameter upon movement from supine to upright position. We hypothesized that the decrease in optic nerve sheath diameter upon gravitational challenge would cease after closure of the leak. METHODS: We included 29 patients with spontaneous intracranial hypotension and refractory symptoms admitted from 2013 to 2016. The systematic workup included: Optic nerve sheath diameter sonography, spinal MRI and dynamic myelography with subsequent CT. Microsurgical sealing of the cerebrospinal fluid leak was the aim in all cases. RESULTS: Of 29 patients with a proven cerebrospinal fluid leak, one declined surgery. A single patient was lost to follow-up. In 27 cases, the cerebrospinal fluid leak was successfully sealed by microsurgery. The width of the optic nerve sheath diameter in supine position increased from 5.08 ± 0.66 mm before to 5.36 ± 0.53 mm after surgery ( p = 0.03). Comparing the response of the optic nerve sheath diameter to gravitational challenge, there was a significant change from before (-0.36 ± 0.32 mm) to after surgery (0.00 ± 0.19 mm, p < 0.01). In parallel, spontaneous intracranial hypotension-related symptoms resolved in 26, decreased in one and persisted in a single patient despite recovery of gait. CONCLUSIONS: The sonographic assessment of the optic nerve sheath diameter with gravitational challenge can distinguish open from closed spinal cerebrospinal fluid fistulas in spontaneous intracranial hypotension patients. A response to the gravitational challenge, that is, no more collapse of the optic nerve sheath while standing up, can be seen after successful treatment and correlates with the resolution of clinical symptoms. Sonography of the optic nerve sheath diameter may be utilized for non-invasive follow-up in spontaneous intracranial hypotension.

Intracranial Hypotension with Coma: Microsurgical Repair of a Spinal Ventral Dural Tear and Drainage of Subdural Hematoma with Intracranial Pressure Monitoring.

BACKGROUND: Difficulties are associated with the diagnosis and management of patients with coma because of intracranial hypotension. CASE DESCRIPTION: A 70-year-old man with coma (Glasgow Coma Scale score of 6) with fixed dilated pupils because of severe intracranial hypotension is described. After unsuccessful epidural blood patch (EBP), the patient underwent microsurgical dural repair and drainage of hematoma with intracranial pressure (ICP) monitoring. Intraoperatively, a dural tear associated with a cerebrospinal fluid (CSF) leak was identified at the thoracolumbar junction ventral to the spinal cord. The dural tear was repaired using posterior laminoplasty with a transdural approach without spinal fixation. Immediately after surgery, ICP was low, but it recovered to a physiologic range in 4 hours. Consciousness level favorably improved in a week, and the patient has remained stable for 1.5 years with good quality of life without recurrence. CONCLUSIONS: The patient represents the first described case, to our knowledge, of intracranial hypotension with coma because of a CSF leak caused by a spinal ventral dural tear. In the setting of failed EBP attempt, our technique may be a treatment option for severe intracranial hypotension.

Central Herniation Induced by Craniotomy Prompting Air Replacement for Subdural Fluid Collection Due to Cerebrospinal Fluid Hypovolemia.

BACKGROUND: Chronic subdural hematoma (CSDH) often occurs in association with cerebrospinal fluid (CSF) hypovolemia. Many cases with CSDH due to CSF hypovolemia and treated by burr hole surgery have been reported to present with paradoxical deterioration. However, the mechanisms and pathology of deterioration after surgery for CSDH due to CSF hypovolemia remain obscure. CASE DESCRIPTION: We report herein a 62-year-old man with gait disturbance due to subdural fluid collection (SDFC) who underwent burr hole irrigation and additional craniotomy, in which postoperative deterioration resulted from rapidly progressing central herniation with a large amount of air accumulation. Epidural blood patch with saline infusion in the thoracic spine finally resolved central herniation. CONCLUSION: SDFC deteriorating after surgery has never been reported. SDFC has communication with CSF differing from mature CSDH composed of closed cavity surrounded by neomembrane. Under situations of CSF hypovolemia due to spinal dural tear, opening the cranium can prompt air replacement in the CSF space, which might represent a substantial risk for central herniation caused by a rapid loss of buoyancy force.

Behavioral Variant Frontotemporal Dementia as a Serious Complication of Spontaneous Intracranial Hypotension.

BACKGROUND: Behavioral variant frontotemporal dementia (bvFTD) is a devastating early onset dementia. Symptoms of bvFTD may be caused by spontaneous intracranial hypotension (SIH), a treatable disorder, but no comprehensive study of such patients has been reported. OBJECTIVE: To describe detailed characteristics of a large cohort of patients with SIH and symptoms of bvFTD. METHODS: We identified patients with SIH who met clinical criteria for bvFTD. Patients were compared to a cohort of SIH patients without bvFTD. RESULTS: The mean age for the 21 men and 8 women was 52.9 yr (range, 37-65 yr). All 29 patients with bvFTD symptoms had hypersomnolence. Magnetic resonance imaging showed brain sagging in all patients, cerebrospinal fluid (CSF) opening pressure low in about half of patients, but a spinal CSF leak could not be detected in any patient. All patients underwent epidural blood patching, but 26 patients eventually underwent 1 or more surgical procedures. Overall, a good outcome was obtained in 21 patients (72%); 20 (91%) of 22 patients who had not undergone prior Chiari surgery compared to 1 (14%) of 7 patients who did undergo Chiari surgery (P < .003). Compared to SIH patients without symptoms of bvFTD (n = 547), those with bvFTD symptoms were older, more often male, less often demonstrated CSF leak on spinal imaging, and more often underwent surgery (P < .02). CONCLUSION: bvFTD in SIH is rare and associated with brain sagging and hypersomnolence. Spinal CSF leaks are rarely detected. bvFTD symptoms are often refractory to the usual percutaneous procedures but most patients can be cured.

Ossified ligamentum flavum of the thoracic spine presenting as spontaneous intracranial hypotension: case report.

Ossification of the ligament flavum in the thoracic spine is an uncommon radiological finding in the Western population but can present with back pain, varying degrees of myelopathy, and even paraplegia on occasion. The authors here present the case of a 50-year-old woman with a history of progressive back pain and symptoms of spontaneous intracranial hypotension who was found to have an ossified ligamentum flavum of the thoracic spine resulting in a dural erosion cerebrospinal fluid leak. Surgery involved removal of the ossified ligament flavum at T10-11, facetectomy, ligation of the nerve root, and primary closure of the dura, which resulted in complete resolution of the patient's symptoms. Radiological, clinical, and intraoperative findings are discussed to assist surgeons with an accurate diagnosis and treatment in the setting of this unusual presentation.